Chunli Zhao, 67, worked for decades at one of the two agricultural business sites where the shooting unfolded on Monday afternoon.
He was arrested soon after when he was spotted sitting in his car outside a local sheriff’s office. Video showed officers wrestling him to the ground and placing him in handcuffs.
The alleged gunman shot dead four victims and wounded a fifth at the Mountain Mushroom Farm, and fatally shot another three victims at the Rice Trucking-Soil Farm located around two miles away, according to authorities. The eighth victim was airlifted to hospital and is now in a stable condition.
The horror attack is believed to have been witnessed by many children, as many farm workers live on-site with their families.
Police said on Tuesday that Zhao obtained the gun legally and characterised the incident as a “workplace violence incident”.
The arraignment is expected tomorrow in San Mateo County.